Effects of molasses levels and growing conditions on nutritive value and fermentation quality of Opuntia cladodes silage

Abstract

The spineless Opuntia ficus-indica fruit (Prickly pear) industry in South Africa has increased in recent years and large quantities of cladodes are produced as a feed source for livestock. The objective of the study was to determine the effect of molasses levels and growing conditions on nutritive value and fermentation characteristics of Opuntia cladodes silage. The cladodes were removed by pruning from a Shaloom Farm outside Mahikeng in Burhmansdrift, North West Province. The following parameters were determined: dry matter, crude protein, acid detergent fibre, neutral detergent fibre, ether extract, pH, lactic acid and water-soluble carbohydrates. There were significant varietal, growing condition and molasses inclusion level interaction effects (P<0.05) on dry matter, moisture, crude protein, neutral detergent fibre, acid detergent fibre and fat contents. The inclusion of molasses (at 8%, 16% and 24%) into different types of prickly pear cladodes resulted in lower dry matter content as compared to without inclusion (0%) of molasses. The reason could be due to high moisture content produced during fermentation. Addition of molasses into prickly pear cladodes in this study resulted in lower acid detergent fibre; neutral detergent fibre and ether extract contents. The higher inclusion levels of molasses for variety Roedtan in both dry and irrigated lands resulted in a higher crude protein content. Lactic acid content from different cladode silages in this study varied from 46.5 to 100 g/kg DM. Animal performance testing to measure the digestibility and palatability of these two promising varieties is recommended to evaluate their effectiveness under practical feeding conditions.